Over the past ten years Jacqueline Wilson has been the most borrowed author from British libraries.
She's sold 30 million of her books just in the UK - and written nearly a hundred of them over the years - girls love them.
They almost always focus on a young girl in a difficult family usually being brought up single-handedly by her mother, sometimes with an abusive stepfather.
And often featuring drink or drugs.
So why does she draw on such bleak territory?
Jacqueline Wilson talks to Sarah Montague
